Study Population and Baseline Values
The medical records of 511 pregnant women in our center were reviewed for enrollment. Among them, 55 of 236 patients were diagnosed and assigned to AFLP group. The details satisfied Swansea criteria were shown in suppl table 1.The number of deliveries were about 214209 from 2009-2018 and the ratio of AFLP was 2.56/1000 in our hospital,which was higher than common population.220 patients without AFLP or other liver diseases were selected and assigned to control group. The patients disposition was shown in Fig 1.
The clinical characteristics of patients in each group was shown in Table 1. When compared to mothers without AFLP (control group), patients with AFLP were significantly younger (28.53±4.71vs.31.31±4.20,P<0.001). Rates of pregnancy induced hypertension (21.8% vs. 2.7%, P<0.001), twins (10.9%vs.1.4%, P=0.002), fetal growth restriction (FGR) (7.3% vs. 1.4%, P=0.044) and male fetus (96.4% vs 55%, P<0.001) before the diagnosis of AFLP were higher in AFLP group than control group. The incidence of gestational diabetes seems less in AFLP group than in control group (5.5% vs.13.2%), but was not significant(P=0.11). There were no difference of other pathological pregnancy between groups. The mean value of ALT (219.18±240.11 vs. 14.35±27.65), total bilirubin (160.83±112.54 vs. 9.33±5.44), TBA (89.45±56.89 vs. 3.26±4.11) and CRE (162.91±89.84 vs. 46.83±11.62) were significantly higher in AFLP group than in control. And the mean value of PLT (130.53±70.16 vs. 205.35±56.03), HGB (104.27±23.44 vs. 120.13±12.40), albumin (25.54±4.67 vs. 33.26±3.99) and prothrombin activity (40.44±23.37 vs. 119.05±13.23) were significantly lower in AFLP group than in control. Also, the incidence of hypoglycemia (61.8% vs.20.9%) was significantly higher in AFLP group than in control.
Characteristics and outcomes of the AFLP patients in our center
The clinical characteristics of the AFLP patients from the chosen studies were summarized in Supplemental Table 1. Among all patients of AFLP group, 3 (5.5%) were diagnosed in the postpartum period. The mean gestational week was 35.25±5.80 weeks in patients diagnosed before delivery and the mean days were 2.33±0.57 days in patients diagnosed after delivery. The median duration from diagnosis to delivery was 1.55±4.62 days and 75% (39/52) pregnancies were terminated at the day of diagnosis.More patients received cesarean section (74.5% vs.49.5%) to terminate the pregnancy. 53.6% (22/41) of AFLP patients received preventive plasma transfusion before surgery. Mean gestational weeks at delivery were 36.26±2.58 weeks in AFLP group, which were significant earlier than control(P=5.47*10-10). During perinatal period, more patients intrauterine balloon tamponade (21.8% vs.3.2%, P<0.05), preventive plasma transfusion (40% vs.0%, P<0.05), hysterectomy (or uterine artery embolism) (5.5% vs.0%, P<0.05), blood transfusion (61.8% vs.1.8%, P<0.05) and intensive care unit admission (61.8% vs.0.9%, P<0.05)in AFLP group than control. No one received artificial liver support or liver transplantation during the treatment.
As is show in table 2, there were a significantly higher frequency of obstetrical complications in AFLP group than control: placental abruption (12.7% vs.0.5%), meconium stained (II-III)(40% vs.8.6%), and postpartum hemorrhage (52.7% vs.12.3%). No difference was found of oligohydramnios (7.3% vs.6.4%) between two groups. After termination of pregnancy, more patients in AFLP group had problem healing wound of episiotomy or abdominal section than control (14.5% vs. 0.5%, P<0.05).In terms of non-obstetrical complications, 83.6% coagulation disorders, 47.3% acute hepatic failure, 85.5% renal insufficiency, 98.2% rising of total bile acids, 47.3% ascites , 18.2% encephalopathy, 3.6% hepatorenal syndrome,7.3% MOF, 1.8% shock and 12.7% infections (2 fungi infection ,1 severe pneumonia, 1acute pancreatitis, 1 bacterial peritonitis,1 biliary tract infection and 1 pressure sore) were found in AFLP group. However, only one patient with slight coagulation disorders and 2.3% patients with rising of total bile acids were found in control. Finally, three mothers in AFLP group were died of multiple organ system failure and 1mother did not completely recovered for two weeks. In terms of fetal/infant complications, a significantly higher frequency of preterm delivery (47.5% vs.5.4%, P<0.05), fetal distress(45.9% vs.3.1%, P<0.05), asphyxia of newborn (24.6% vs.0.9%, P<0.05), NICU admission (19.7% vs.1.3%, P<0.05) and fetal/infant death(9.8% vs.0, P<0.05 ) were found in AFLP group than in control group.
When compared to those without negative outcomes, predictors of negative fetus and infants outcomes were younger mothers (27.00±2.57 vs.29.21±5.28), more singleton rates (100% vs.72.73%), higher mean values of ALT (328.80±277.48 vs. 164.60±194.25) and T-Bilirubin (208.46±108.89 vs. 130.63±107.46), lower mean value of prothrombin activity (29.51±23.10 vs. 46.50±22.31) (supp table 2). Besides, more patients in this group received preventive plasma transfusion (70.6% vs.27.3%) and intrauterine balloon tamponade (47.1% vs.15.9%). There were no predictors of negative maternal outcomes found in baseline values (suppl table 3).
The role of intrauterine balloon tamponade in preventing future postpartum hemorrhage
To evaluate the role of intrauterine balloon tamponade, we stratified 28 patients with postpartum hemorrhage more than 500ml into group A (patients received intrauterine balloon tamponade) and group B (patients received other methods instead of intrauterine balloon tamponade). Compared to patients in group B, less patients were found in group A suffered from refractory postpartum hemorrhage (>2000ml in delivery) (0% vs.31.3%, p =0.101 ), hysterectomy (0% vs.12.5%, p=0.596), negative maternal outcomes (16.7% vs.56.3%, p=0.083). But none of them had statistical significance due to restricted sample size (table 3).